The use of reinforced composites made of particulate fillers or reinforcing fibres has been gaining popularity in dental and medical fields. Several fibre reinforced composites are already known. The state-of-the-art fibre reinforced composites yield high strength properties and by selecting the multiphase resin matrix for the composite, the handling characteristics of the composite can be considerably improved. These have been described, for example, in the patent applications WO 96/25911 and WO 99/45890.
On the other hand, a lot of development has occurred with bioactive materials, namely bioactive ceramics and glass and sol-gel processed silica. These materials can be used to achieve attachment of e.g. bone to a biomaterial surface after the material has been put in contact with tissue. An additional advantage of bioactive glass is its antimicrobial effect on the microbes existing for instance in sinuses of a bone. These properties have been described in several articles and patent applications, such as WO 96/21628 and Zehnder et al., J Endod 2004 April; 30(4):220-4.
From a surgical perspective individual replacement of bone, cartilage and soft tissues are insufficient in tumour, traumatologic and tissue reconstruction surgery despite the increasing advances in biomaterials research and their clinical application methods and tissue engineering. The need and indications for development of new kinds of materials result from disadvantages of the use of allografts. Risks for transmittable diseases (HIV, Creutzfeld-Jacob's disease, etc.) are related to allografting. Metals are not bioactive or osteoconductive, and their use results in stress shielding phenomena and bone atrophy of the adjacent bone. Metal implants cause also severe problems in magnetic resonance imaging (MRI) when diagnosing diseases of patients. These main disadvantages are well documented in large clinical series. On the other hand, medical treatments based on stem cells are becoming an option for treating tissue damages. Stem cell treatment in large reconstruction cases requires use of scaffolds with certain porosity. Currently, the scaffolds are made of biodegradable polymers and non-resorbable porous fibre reinforced composites have not been used for combining regenerative treatment stem cells and reconstructive treatment by fibre composite implants.
Document US 2007/0061015 discloses a biocompatible implement for bone and tissue regeneration having a layered structure. The layered structure can be reinforced by adding strips on the outer surface of the implement. In document US 2004/0258732 an implant material is made by combining a porous article and a pin penetrating through the porous article.
Several different composites comprising bioactive material and imitating bone structure have been presented, for example in applications WO 2004/103319 and WO2005/118744. A problem encountered with these materials is their insufficient mechanical strength. Another problem with these materials is the weak attachment of the porous material (having a low degree of impregnation with the matrix resin) to the load bearing material. A yet further problem is that the particles that are added to the material to enhance the osteoconductivity tend to get loose and disappear from the material before it is placed into the final position.